Nerf Tesla

Nerf Tesla

Inventor: Rob Flickenger

Where: Seattle

Age: 37

This self-proclaimed mad scientist turned a Nerf gun into the ultimate sci-fi sidekick. "Not long ago, I picked up [the graphic novel] The Five Fists of Science, all about Nikola Tesla and Mark Twain battling the evil Thomas Edison," Flickenger says. "Tesla carries these steampunk guns that fire lightning bolts—I had to have one." Not even the sky-high voltage generated by a spark-gap tesla coil could deter him. A tech writer by day, Flickenger designed the porcelain-and-tungsten switch at the heart of the system on a 3D printer. The output is tied to a flyback transformer from an old TV, and six Cornell Dubilier capacitors sit in a laser-cut housing atop the weapon. The device is powered by an 18-volt lithium-ion battery. When paired with the circuit nestled inside a PVC end cap, those 18 volts turn into nearly 200,000. "That capacitor bank could kill you twice before you hit the ground," Flickenger says. In other words, try not to play with it in the house.

Compact Go-Karts

Compact Go-Karts

Inventor: Charles Guan

Where: Cambridge, Mass.

Age: 23

Think of it as bringing horsepower to the people. On a whim last spring, the MIT masters student built a mini go-kart—or Chibikart—with custom-machined hub motors and a massive 33-volt lithium-ion battery. Amateur builders cheered the accomplishment online—and then furrowed their collective brow. "People were dismissing it as a privileged college kid project," Guan says. "So I decided to make a democratized version." Powered by a pair of standard 12-volt lithium iron phosphate batteries, the two-wheel-drive Chibikart 2 roams the school hallways on 4-inch rubber tires. The twin 1-hp drive motors were designed for RC model aircraft. "They're some of the best power-to-weight-ratio parts available for any kind of propulsion," Guan says. The 36-pound chariot stops thanks to brakes fashioned mostly from stock bicycle parts. Top speed? About 22 mph, which means Guan may want to think about buying himself a helmet.